Display apparatus and driving method thereof

ABSTRACT

A display apparatus includes a display including a plurality of display modules, a display driver including a plurality of driving modules respectively connected to the plurality of display modules, a storage storing current information concerning a plurality of display modules, and a processor calculating a peak luminance level of each of a plurality of display modules based on individual power consumptions of each of a plurality of display modules and controlling a plurality of driving modules using the current information stored in the storage based on the calculated peak luminance level.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2016-0109483, filed on Aug. 26, 2016 in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference in its entirety.

BACKGROUND 1. Field

Devices and methods consistent with exemplary embodiments relate to adisplay apparatus and a driving method thereof, and more specifically,to a display apparatus provided with a display configured with aspontaneous emission pixels that are driven by electric currents and adriving method thereof.

2. Description of Related Art

A light emitting diode (LED) is a semiconductor emitting device forconverting electric currents into light. Recently, as luminance of LEDgradually increases, LED devices are increasingly used as a displaylight source, automobile light source and illumination light source.Further, LEDs that emit white light with excellent efficiency can alsobe implemented by using a fluorescent material or combining variouscolors of LEDs.

Such LED can display an image with high luminance with a high current.However, LEDs driven at such high currents have a problem of related toa color shift phenomenon.

Specifically, red, blue and green LEDs, necessary for implementingvarious colors, have a problem of screen quality deterioration when thecurrents increase because different color shift phenomenon occursaccording to increase of the applied currents.

SUMMARY

Exemplary embodiments may overcome the above disadvantages and otherdisadvantages not described above. Also, exemplary embodiments are notrequired to overcome the disadvantages described above, and an exemplaryembodiment may not overcome any of the problems described above.

According to an aspect of an exemplary embodiment, there is provided adisplay apparatus including: a display including a plurality of displaymodules; a display driver including a plurality of driving modulesrespectively connected to the plurality of display modules; a storageconfigured to store current information concerning the plurality ofdisplay modules; and a processor configured to calculate a peakluminance level of each of the plurality of display modules based onindividual power consumptions of each of the plurality of displaymodules, and control the plurality of driving modules using on thecurrent information stored in the storage based on the calculated peakluminance level.

Each of the plurality of display modules may include sub pixels, and thecurrent information may include current control information according toluminance of each sub pixel of the plurality of display modules.

The current control information may be calibrated based on a luminancecharacteristic and a color shift characteristic according to a pluralityof current levels of each sub pixel of the plurality of display modules.

The processor may be further configured to obtain, from the storage, acurrent gain value of each sub pixel of the plurality of displaymodules, and control a driving state of each of the plurality of drivingmodules based on the obtained current gain values to reach therespective calculated peak luminance levels.

The processor may be further configured to calculate a peak luminancelevel of each of the plurality of display modules based on: a maximumpower consumption among the individual power consumptions of each of theplurality of display modules; and a rated capacity of each of theplurality of driving modules.

The storage may further store luminance level information of a pluralityof power levels provided to each of the plurality of display modules,and the processor may be further configured to determine a referencedisplay module of the plurality of display modules, the referencedisplay module consuming more power than remaining display modules ofthe plurality of display modules, determine a power increase of thereference display module, determine a corresponding power increase ofeach remaining display module based on a power increase of the referencedisplay module, and calculate a peak luminance level of each displaymodule based on a maximum power amount calculated for each displaymodule and the luminance level information of each of the plurality ofpower levels.

The storage may further store the luminance level information of aplurality of power levels provided to each of the plurality of thedisplay modules, and the processor may be further configured todetermine a reference display module of the plurality of displaymodules, the reference display module consuming more power thanremaining display modules of the plurality of display modules, calculatea reference peak luminance level of the reference display module basedon maximum luminance level information of each of the plurality of powerlevels, and calculate a peak luminance level of each of the remainingdisplay modules based on the calculated reference peak luminance level.

The storage may further store power information of each sub pixel pergray scale of an image, and the processor may be further configured tocalculate a power consumption of each of the plurality of displaymodules based on a gray scale value of an image displayed on each of theplurality of display modules and the power information of each sub pixelper gray scale.

Each of the plurality of display modules may include an LED cabinetincluding a plurality of LED devices, and the current information mayinclude current information corresponding to each of a red LED, a greenLED and a blue LED.

According to an aspect of another exemplary embodiment, there isprovided a method of driving a display apparatus including a pluralityof display modules respectively connected to a plurality of drivingmodules, the method including: calculating a peak luminance level ofeach of the plurality of display modules based on individual powerconsumptions of each of the plurality of display modules; and drivingthe plurality of display modules using current information correspondingto each of the plurality of display modules based on the calculated peakluminance level.

Each of the plurality of display modules includes sub pixels, and thecurrent information may include current control information according toluminance of each sub pixel of the plurality of display modules.

The current control information may be calibrated based on a luminancecharacteristic and a color shift characteristic according to a pluralityof current levels of each sub pixel of the plurality of display modules.

The driving the plurality of display modules may include: obtaining acurrent gain value of each sub pixel of the plurality of displaymodules; and driving the plurality of display modules based on theobtained current gain value, to reach the respective calculated peakluminance levels

The calculating the peak luminance level may include calculating a peakluminance level of each of the plurality of display modules based on: amaximum power consumption among the individual power consumptions ofeach of the plurality of display modules; and a rated capacity of eachof the plurality of driving modules.

The calculating the peak luminance level may include: determining areference display module of the plurality of display modules, thereference display module consuming more power than remaining displaymodules of the plurality of display modules; determining a correspondingpower increase of each remaining display module based on a powerincrease of the reference display module; and calculating a peakluminance level of each display module based on luminance levelinformation of each of the plurality of power levels and a maximum poweramount calculated for each display module.

The calculating the peak luminance level may include: determining areference display module of the plurality of display modules, thereference display module consuming more power than remaining displaymodules of the plurality of display modules; calculating a referencepeak luminance level of the reference display module based on maximumluminance level information of each of the plurality of power levels;and calculating a peak luminance level of each of the remaining displaymodules based on the calculated reference peak luminance level.

The calculating the peak luminance level may include calculating thepower consumption of each of the plurality of display modules based onpower information of each sub pixel per gray scale of an image and agray scale value of an image displayed on each of the plurality ofdisplay modules.

Each of the plurality of display modules may include an LED cabinetincluding a plurality of LED devices, and the current information mayinclude current information corresponding to each of a red LED, a greenLED and a blue LED.

According to an aspect of yet another exemplary embodiment, there isprovided a display apparatus including: a plurality of display modules;a plurality of driving modules configured to respectively drive theplurality of display modules; and a processor configured to control theplurality of driving modules to display an image on the plurality ofdisplay modules, determine a high power driving module among theplurality of driving modules based on power required by each of theplurality of driving modules to display the image, determine a powerincrease based on power consumed by the high power driving module and apower capacity of the high power driving module, and drive anotherdriving module of the plurality of driving modules based on the powerincrease.

The processor may be further configured to determine the power increaseby dividing the power capacity by power required by the high powerdriving module to display the image, and apply power to the anotherdriving module at an increased level corresponding to an initial powerconsumption of the another driving module multiplied by the powerincrease rate.

The processor may be further configured to determine the power increasebased on a difference between power required by the high power drivingmodule to display the image and the power capacity, and apply power tothe another driving module at an increased level corresponding to a sumof an initial power consumption of the another driving module and thepower increased multiplied by a weighted value corresponding to theanother driving module.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects will be more apparent by describingcertain exemplary embodiments with reference to the accompanyingdrawings, in which:

FIG. 1 is a diagram illustrating a display apparatus according to anexemplary embodiment;

FIGS. 2A and 2B are a block diagrams illustrating a display apparatusaccording to an exemplary embodiment;

FIGS. 3A and 3B are diagrams describing a method for calculating powerconsumption of each display module according to an exemplary embodiment;

FIG. 4 is a diagram illustrating power information of each sub pixel pergray scale of an image according to an exemplary embodiment;

FIG. 5 is a diagram illustrating maximum luminance level incrementinformation of each power provided to a display module according to anexemplary embodiment;

FIG. 6 is a diagram illustrating current gain information per luminanceof each sub pixel according to an exemplary embodiment;

FIG. 7 is a diagram illustrating luminance characteristics of red, blueand green LED devices according to increase of a current forunderstanding of the present disclosure;

FIGS. 8A, 8B and 8C are diagrams describing color shift characteristicsof red, blue and green LED devices according to increase of a currentfor understanding of the present disclosure; and

FIG. 9 is a flowchart describing a driving method of a display apparatusaccording to an exemplary embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments will now be described in greater detail withreference to the accompanying drawings.

In the following description, same drawing reference numerals are usedfor the same elements even in different drawings. The matters defined inthe description, such as detailed construction and elements, areprovided to assist in a comprehensive understanding, and exemplaryembodiments can be carried out without those specifically definedmatters. Also, well-known functions or constructions are not describedin detail for conciseness.

FIG. 1 is a diagram illustrating a display apparatus according to anexemplary embodiment.

Referring to FIG. 1, a display apparatus 100 according to an exemplaryembodiment may be implemented by physically connecting a plurality ofdisplay modules 110-1, 110-2, 110-3, 110-4, . . . 110-12. Herein, eachof the plurality of display modules may include a plurality of pixelsarranged in a matrix form. The pixels may be, for example, spontaneousemission pixels. Specifically, the display modules may be an LED modulein which each of a plurality of pixels is an LED pixel, or an LEDcabinet in which a plurality of LED modules are connected. However,these are examples, and exemplary embodiments are not limited to theabove. For example, the display module may be implemented as a liquidcrystal display (LCD), an organic LED (OLED), an active-matrix OLED(AMOLED), or a plasma display panel (PDP). However, exemplaryembodiments will be described below based on assumption that each of thedisplay modules is implemented as an LED cabinet for convenientexplanation.

An LED is an optical semiconductor device that converts electricalenergy into light energy. Further, an LED is one type of a p-n junctiondiode, and while generating light, electrons of an n region moves to a pregion with current provided externally, electrons and electron holesare recombined at a junction, and electrons are reverted to a groundstate, resulting in emission of an energy, i.e., a light. A wavelengthof the emitting light may be formed in various shapes according to anenergy band value, and light colors may be determined according to thewavelength. Further, an LED is a current driving device in whichluminance may be vary according to the applied current, and each color,red, green and blue, may have a different resistance value. Therefore,because each applied electrical power may be different when the samecurrent and voltage are applied, there may be a difference in luminanceper LED. Further, an LED may experience a color shift phenomenonaccording to increase of the applied current, and may have differentcolor shift values depending on the LED color.

Therefore, when current values increase en bloc to implement a highluminance on an LED display, screen quality deterioration may occur dueto the luminance variation and the color shift phenomenon. Below,various LED driving methods consistent with one or more exemplaryembodiments are discussed that can prevent screen quality deteriorationdue to such LED characteristics.

FIG. 2A is a block diagram illustrating a display apparatus according toan exemplary embodiment.

Referring to FIG. 2A, the display apparatus 100 includes the display110, a display driver 120 and a storage 130.

The display 110 may include a plurality of display modules.Specifically, the display 110 may be configured in such a form in whicha plurality of display modules 110-1, . . . , 110-n are connected andassembled. Herein, each of a plurality of display modules may include aplurality of pixels arranged in a matrix form, and the plurality ofpixels may be spontaneous emission pixels. According to an exemplaryembodiment, the display 110 may be implemented to include a plurality ofLED modules, each LED module including at least one LED device, and/or aplurality of LED cabinets. Further, LED modules may include a pluralityof LED pixels; according to an exemplary embodiment, LED pixels may beimplemented as LEDs, including a red LED, a green LED, and a blue LED.

The display driver 120 may drive the display 110 according to control ofa processor 140. For example, the display driver 120 may apply a drivingvoltage or have a driving current to flow in order to drive eachspontaneous emission device constituting the display panel 110, e.g.,drive LED pixel, according to control of the processor 140.

The display driver 120 may include a plurality of LED driving modules120-1, . . . , 120-n respectively connected to a plurality of displaymodules 110-1, . . . , 110-n. A plurality of LED driving modules 120-1,. . . , 120-n may drive a plurality of display modules 110-1, . . . ,110-n by providing the driving current to a plurality of display modules110-1, . . . , 110-n correspondingly to each control signal inputtedfrom the processor 140 which will be described below.

Specifically, a plurality of LED driving modules 120-1, . . . , 120-nmay adjust and output supply time or intensity of the driving currentprovided to a plurality of display modules 110-1, . . . , 110-naccording to each control signal inputted from the processor 140.

Each of a plurality of LED driving modules 120-1, . . . , 120-n mayinclude a power supply for providing electrical power. The power supplyis hardware for converting alternating current into the direct currentand providing the electrical power to be suitable for each system. Thepower supply may be include an input electromagnetic interference (EMI)filter, an alternating-direct rectifier, a direct-direct switchingconverter, an output filter, and an outputter. The power supply may be aswitched mode power supply (SMPS), for example. An SMPS may be a directstabilization electrical power device stabilized with the output byon-off time ratio control of a semiconductor switch device, which mayprovide high efficiency, miniaturization, and light-weight and thus beused in driving each of a plurality of display modules 110-1, . . . ,110-n.

However, according to another exemplary embodiment, the display driver120 may be implemented as one driving module which separately drives aplurality of SMPS for providing the electrical power to each of aplurality of display modules 110-1, . . . , 110-n.

According to various exemplary embodiments, a plurality of displaymodules 110-1, . . . , 110-n may respectively include a sub processorfor controlling operation of each display module and a driving modulefor driving each display module according to control of the subprocessor. In this case, the sub processor and the driving module may behardware, software, firmware or an integrated chip (IC). According to anexemplary embodiment, each sub processor may be implemented as aseparate semiconductor IC.

The storage 130 may store various data necessary for operation of thedisplay apparatus 100.

The storage 130 may be a non-volatile memory, volatile memory, hard diskdrive (HDD), or solid state drive (SSD), a memory card attached with thedisplay apparatus 100 (e.g., micro SD card, USB memory), and an externalmemory that can be connected with an external input port (e.g., USBmemory).

Specifically, the storage 130 may store current information of aplurality of display modules 110-1, . . . , 110-n. Herein, the currentinformation may be current control information according to luminance ofeach sub pixel constituting the display module. The current controlinformation according to luminance of each sub pixel may be calibrated(modeled) based on luminance characteristics and color shiftcharacteristics according to the current of each sub pixel.

Specifically, the current control information according to luminance ofeach sub pixel may be current gain information according to luminance ofeach sub pixel, which is calibrated based on luminance level informationaccording to the current of each sub pixel and color shift informationaccording to the current of each sub pixel. For example, the luminancelevel information according to the current of each sub pixel may beluminance change information according to the current change of eachR/B/G LED device, and the color information according to the current ofeach sub pixel may be degrees of variations of the color coordinates(e.g., x, y color coordinates) according to the current change of eachR/B/G LED device.

In this case, the current gain information according to luminance ofeach sub pixel may be obtained by calibrating current values so thatluminance change of each R/B/G LED device according to the currentchange is similar, and by calibrating current values so that the colorshift phenomenon of each R/B/G LED device is not generated according tothe current change.

However, exemplary embodiments are not be limited to the examplesprovided above. According to one or more exemplary embodiments, thecurrent control information may be current values instead of currentgain values.

Further, the storage 130 may store luminance level information of eachpower level provided to the display module. Luminance of the displaymodule increases as power provided to the display module increases.However, when the power supplied exceeds a preset threshold value, aluminance increase rate of the display module may gradually decrease,and may not increase by more than a maximum luminance value.Accordingly, information regarding luminance change of the displaymodule according to the supply power change may be previously measuredand stored in the storage 130.

In this case, the luminance level information of each power may beluminance increase information according to power increase. However,even when the above form of information is not provided, any informationrepresenting relations between the power supply and luminance may beapplied without limitations.

Further, the storage 130 may store power information of each sub pixelper gray scale. Because the gray scale of an image is related to aluminance value, power of each LED device necessary for expressing apreset gray scale of an image may change. As a result, the powerinformation of each LED device per gray scale of an image may be storedin the storage 130.

For example, in case of 255 gray scale value (when an image has 256steps of gray scale regarding each color signal of red, green and blue)or 1024 gray scale value (when an image has 1024 steps of gray scaleregarding each color signal of red, green and blue), the powerinformation of each LED device per gray scale may be stored in thestorage 130. Such power information of each gray scale may be previouslymeasured and stored in the storage 130. Thus, while an image of eachgray scale is respectively displayed on the display module, the powerinformation of each gray scale may be obtained by measuring an amount ofpower consumed in LED device.

Besides, the storage 130 may store information regarding binning group,information regarding maximum luminance of each pixel, informationregarding color of each pixel, and a luminance correction coefficient ofeach pixel. Herein, the binning group may be LED pixel group havingmaximum uniform characteristics (luminance, color coordinate) withrespect to LED pixels.

For example, in order to adjust maximum luminance to a target luminancefor uniformity between a plurality of LED pixels, the luminance may belowered through the calibration by using a luminance correctioncoefficient. In this case, the luminance correction coefficient may bein a 3*3 matrix form to implement the target red, green and blueluminance, the maximum luminance may be a target luminance obtained byapplying different luminance correction coefficients to each pixel,thereby implementing uniformity. Further, while implementing the targetluminance in a 3*3 matrix form of parameters corresponding to each LEDelement, a color temperature may be also calibrated to obtainuniformity.

Further, the storage 130 may store information regarding a number ofpixels constituting each of a plurality of display modules, a size ofthe pixels and an internal distance between the pixels.

Meanwhile, according to another exemplary embodiment, the abovedescribed information stored in the storage 130 may be obtained from anexternal device. For example, a portion of the information may bereceived in real time from an external device such as set-top box,external server, and user terminal.

The processor 140 may control overall operation of the display apparatus100. The processor 140 may include one or more among a centralprocessing unit (CPU), a controller, an application processor (AP), acommunication processor (CP), and an ARM processor.

Further, the processor 140 may include a graphic processing unit forgraphic processing corresponding to an image. The processor 130 may beimplemented as a system on chip (SoC) including a core and a GPU. Theprocessor 130 may include a single core, a dual core, a triple core, aquad core and a multiple number of a core.

According to an exemplary embodiment, the processor 140 may calculate apeak luminance level of each of a plurality of display modules 110-1, .. . , 110-n based on a calculated individual power consumptions withrespect to each of a plurality of display modules 110-1, . . . , 110-n.Thereafter, the processor 140 may control each of a plurality of drivingmodules 120-1, . . . , 120-n to have peak luminance levels respectivelycorresponding to a plurality of display modules 110-1, . . . , 110-nbased on the current information of each luminance stored in the storage130.

In this case, the processor 140 may calculate an amount of powerconsumed in each of a plurality of display modules 110-1, . . . , 110-nbased on gray scale values of images displayed on each of a plurality ofdisplay modules 110-1, . . . , 110-n and the power information of eachsub pixel per gray scale obtained from the storage 130.

For example, as illustrated in FIG. 2B, it is assumed that a pluralityof display modules 110-1, . . . , 110-n may be implemented as the firstto fourth display modules 110-1 to 110-4, and may be respectively drivenby the first to fourth driving modules 110-1 to 110-4.

In this case, as illustrated in FIG. 3A, one image frame may be dividedover the first to fourth display modules 110-1 to 110-4 and displayed.In this case, the gray scales corresponding to each of first to fourthimage regions provided to the first to fourth display modules 110-1 to110-4 may be generally different. When one image frame is divided into aplurality of image regions, images respectively included in the dividedimage regions may be each different.

The processor 140 may calculate an amount of power consumed in the firstto fourth display modules 110-1 to 110-4 based on the image gray scalevalues to be expressed by each sub pixel while the first to fourthdisplay modules 110-1 to 110-4 display the first to fourth imageregions. In this case, the processor 140 may calculate an amount ofpower consumed in the first to fourth display modules 110-1 to 110-4based on the power information of each LED device per gray scale storedin the storage 130.

FIG. 4 is a diagram illustrating the power information of each sub pixelper gray scale of an image according to an exemplary embodiment.

For example, as illustrated in FIG. 4, when each LED device expresseseach gray scale value of 1024 gray scale, the consumed amount of powermay be different. Generally, in case of a red LED device, the necessarypower for expressing a uniform gray scale value is relatively greatercompared to a green LED device and a blue LED device, whereas the greenLED device and the blue LED device require a similar amount of power toexpress a uniform gray scale value.

The power values necessary for expressing the gray scale of an image perLED device may be previously stored in the storage 130, and theprocessor 140 may calculate individual power consumptions of each of thefirst to fourth display modules 110-1 to 110-4 based on the previouslystored information.

For example, as illustrated in FIG. 3B, the power consumption of thefirst to fourth display modules 110-1 to 110-4 may be calculated to be60 watts (W), 100 W, 70 W, 50 W, respectively.

Thereafter, the processor 140 may calculate a peak luminance level ofeach of a plurality of display modules 110-1, . . . , 110-n based onindividual power consumptions calculated with respect to each of aplurality of display modules 110-1, . . . , 110-n and a capacity thatcan be provided by a plurality of driving modules 120-1, . . . , 120-n.Herein, a capacity of power that can be provided by a plurality ofdriving modules 120-1, . . . , 120-n may correspond to a capacity of aplurality of power supplies included in each of a plurality of drivingmodules 120-1, . . . , 120-n, i.e., a regular capacity (or regularoutput) of SMPS.

Specifically, the processor 140 may calculate the peak luminance levelof each of a plurality of display modules 110-1, . . . , 110-n based ona maximum power consumption among individual power consumptions of eachof a plurality of display modules 110-1, . . . , 110-n and a capacitythat can be provided by each of a plurality of driving modules 120-1, .. . , 120-n.

Specifically, the processor 140 may determine a maximum power amount ofa reference display module having a maximum power consumption among aplurality of display modules 110-1, . . . , 110-n, and calculate a powerincrease rate based on a power consumption and a maximum power amount ofthe reference display module.

For example, the power increase rate, Pr, may be calculated by dividinga maximum power amount of a reference display module by powerconsumption of the reference display module. Meanwhile, the maximumpower amount of the reference display module may be the same as acapacity that can be provided by each of a plurality of driving modules120-1, . . . , 120-n, but not limited hereto.

Thereafter, the processor 140 may calculate the maximum power amount ofthe other display modules by applying the calculated power increase ratePr to the power consumption of the other display modules. Thus, themaximum power amount of the other display modules may be calculated bymultiplying power consumption of each display module by the powerincrease rate Pr.

For example, as illustrated in FIG. 3B, when the power consumptions ofthe first to fourth display modules 110-1 to 110-4 are respectively 60W, 100 W, 70 W, 50 W and when the maximum power amount of the seconddisplay module 110-2, having a maximum power consumption of 100 W, isdetermined to be a regular capacity, 300 W, the power increase rate maybe 3.

In this case, the processor 140 may apply the power increase rate 3 tothe power consumption of the first, third, and fourth display modules110-1, 110-3, 110-4 and determine the maximum power amount of the first,third, and fourth display modules 110-1, 110-3, 110-4 to be 60 W*3=180W, 70 W*3=210 W, 50 W*3=150 W, respectively.

However, according to various exemplary embodiments, the power increaserate Pr may be applied with a preset weighted value a. Further, thepower increase rate applied to the other display modules may be appliedwith a different weighted value according to a power of each displaymodule, and different power increase rates Pr*α₁, Pr*α₂, Pr*α₃ may becalculated in each display module.

However, this is merely exemplary; a preset weighted value may beapplied based on the power increase in the reference display moduleaccording to another exemplary embodiment, and the power amount appliedwith a weighted value may be determined as the increased power amount ofthe other display modules.

For example, the power increase of the second display module 110-2, 200W, may be applied with a preset weighted value based on the powerconsumption of each display module. For example, the power increaseapplied with the weighted values, β₁, β₂, β₃, which are calculated basedon the power consumptions 60 W, 70 W, 50 W in each of the first, third,and fourth display modules 110-1, 110-3, 110-4, i.e., 200 W*β₁, 200W*β₂, 200 W*β₃ may be determined to be corresponding increased poweramounts. In this case, the maximum power amounts in each of the first,third, and fourth display modules 110-1, 110-3, 110-4 may be 60 W+200W*β₁, 70 W+200 W*β₂, 50 W+200 W*β₃.

Thereafter, the processor 140 may determine the peak luminance level ofeach of a plurality of display modules 110-1, . . . , 110-n based on themaximum luminance level information of each power provided to thedisplay module stored in the storage 130 and based on the maximum poweramount of each of a plurality of display modules 110-1, . . . , 110-n.

FIG. 5 is a diagram illustrating the maximum luminance level incrementfor each power provided to the display module according to an exemplaryembodiment.

For example, the maximum luminance level increment for each power levelmay be shown in a drawing representing the luminance increase accordingto the power increase, as illustrated in FIG. 5. As the power increaserate increases, the luminance amount increasing with respect to auniform power amount may gradually decrease, as illustrated. However,for the information that can be used according to an exemplaryembodiment, any information representing relations between the supplypower and the luminance can be applied, and not limited hereto.

The processor 140 may determine the peak luminance level of each of aplurality of display modules 110-1, . . . , 110-n based on suchinformation.

However, according to another exemplary embodiment, the reference peakluminance level of the reference display module having the maximum powerconsumption among a plurality of display modules 110-1, . . . , 110-nmay be calculated, and the peak luminance level of each of the otherdisplay modules may be calculated based on the calculated reference peakluminance level.

For example, as illustrated in FIG. 3B, when the power consumption ofthe first to fourth display modules 110-1 to 110-4 are respectively 60W, 100 W, 70 W, 50 W, and when the maximum power amount of the seconddisplay module 110-2 having the maximum power consumption of 100 W isdetermined to be a regular capacity of 300 W, the peak luminance levelof the second display module 110-2 may be calculated.

Thereafter, the processor 140 may calculate the peak luminance level ofthe first, third, and fourth display modules 110-1, 110-3, 110-4, basedon the peak luminance level of the second display module 110-2. Forexample, when the peak luminance level of the second display module110-2 is calculated to be A nits, and when the current luminance levelis B nits, the luminance increase ratio A/B, calculated as discussedabove, may be applied to the luminance level of the first, third, andfourth display modules 110-1, 110-3, 110-4. Thus, the peak luminancelevel of each of the first, third, and fourth display modules 110-1,110-3, 110-4 may be calculated.

Meanwhile, the processor 140 may obtain current gain value of each subpixel corresponding to each of a plurality of display modules 110-1, . .. , 110-n so that each of a plurality of display modules 110-1, . . . ,110-n has the calculated peak luminance level, and control a drivingstate of each of a plurality of driving modules 120-1, . . . , 120-nbased on the obtained current gain values of each sub pixel.

In other words, the storage 130 may store the current gain informationper luminance of each sub pixel constituting a plurality of displaymodules 110-1, . . . , 110-n.

FIG. 6 is a diagram illustrating the current gain information perluminance of each sub pixel according to an exemplary embodiment.

Current gain information per luminance of each sub pixel, such as theinformation illustrated in FIG. 6, may include the current gain valueper luminance of each sub pixel, which is calibrated based on theluminance and color properties of each sub pixel according to thecurrent increase.

Specifically, as illustrated in FIG. 7, red, blue and green LED devicesmay have different luminance increase characteristics according to thecurrent increase. Further, as illustrated in FIGS. 8A and 8B, red, blueand green LED devices may have different color shift characteristicsbecause a color coordinate becomes different with different shapesaccording to the current increase. For example, as illustrated in FIG.8A, a red LED device may keep a uniform value of x and y coordinatesaccording to the current increase; however, it a green LED device mayhave slightly modified x, y coordinates, as illustrated in FIG. 8B, andblue LED devices may have considerably modified x, y coordinatesaccording to the current increase, as illustrated in FIG. 8C.

Thereby, the storage 130 may store the electrical gain values perluminance of each LED device, which are calculated by considering theluminance characteristic according to the current of each LED device asillustrated in FIG. 7, and the color property according to the currentof each LED device as illustrated in FIGS. 8A, 8B and 8C. For example,the current gain information may include the current gain values dividedby 2⁸ steps based on 8 bit information, but not limited hereto.

For example, the peak luminance level corresponding to the maximum poweramount, 180 W, 300 W, 210 W, 150 W of each of the first to fourthdisplay modules 110-1 to 110-4 may be respectively determined to be A,B, C, D, and the gain values of the current flowing in each LED devicemay be applied based on the graph of FIG. 6 with respect to a specificcurrent value necessary for implementing each luminance level. In otherwords, a last current value applied with each of the current values a,b, c, d for implementing the peak luminance level of each of the firstto fourth display modules 110-1 to 110-4 and the current gain valuesaccording to the characteristic of each LED device may be applied to thefirst to fourth display modules 110-1 to 110-4.

For example, gain values, g_(r1), g_(g1), g_(b1), to drive each LEDdevice of the first display module 110-1 may be respectively applied tothe corresponding current value a, gain values, g_(r2), g_(g2), g_(b2),to drive each LED device of the second display module 110-2 may berespectively applied to the corresponding current value b, gain values,g_(r3), g_(g3), g_(b3), to drive each LED device of the third displaymodule 110-3 may be respectively applied to the corresponding currentvalue c, and gain values, g_(r4), g_(g4), g_(b4), to drive each LEDdevice of the fourth display module 110-4 may be respectively applied tothe corresponding current values. Therefore, the luminance of the firstto fourth display modules 110-1 to 110-4 may be controlled with the peakluminance level.

FIG. 9 is a flowchart describing a driving method of the displayapparatus according to an exemplary embodiment.

The display apparatus applied with the driving method according to anexemplary embodiment illustrated in FIG. 9 may include the displayconstituted with a plurality of display modules.

According to the driving method of the display apparatus illustrated inFIG. 9, the individual power consumptions of each of a plurality ofdisplay modules may be calculated at S910.

At S920, the peak luminance level of each of a plurality of displaymodules may be calculated based on the calculated power consumption.

At S930, a plurality of display modules may be driven to the peakluminance level corresponding to each of a plurality of display modulesbased on the current information of a plurality of display modules.

In this case, the current information may include the current controlinformation according to the luminance of each sub pixel constitutingthe display module. Specifically, the current information may includethe current control information (e.g., current gain value or currentvalue) according to the luminance of each sub pixel which is calibratedbased on the luminance characteristic and the color shift characteristicaccording to the current of each sub pixel. Meanwhile, the currentinformation may be previously stored in the display apparatus orreceived from an external device (e.g., set-top box, user terminal,server and so on).

Meanwhile, at S920, the calculating the peak luminance level of each ofa plurality of display modules may be based on the maximum powerconsumption of the individual power consumptions of each of a pluralityof display modules and a capacity that can be provided by each of aplurality of driving modules.

Further, a processor may determine a power increase of the other displaymodules based on a power increase of the reference display module havingthe maximum power consumption among the individual power consumptions ofeach of a plurality of display modules, and calculate the peak luminancelevel of each display module based on the maximum power amountcalculated regarding each display module and the luminance levelinformation of each power provided to the display module. Herein, theluminance level information of each power provided to the display modulemay be previously stored in the display apparatus or received from anexternal device (e.g., set-top box, user terminal, server, and so on).

Further, at S920, a reference peak luminance level of the referencedisplay module having the maximum power consumption among a plurality ofdisplay modules may be calculated based on the maximum luminance levelinformation of each power, and the peak luminance level of each of theother display modules may be calculated based on the calculatedreference peak luminance level.

Further, at S930, the current gain values of each sub pixelcorresponding to each of a plurality of display modules, which allowseach of a plurality of display modules to reach the calculated peakluminance level, may be obtained, and a plurality of display modules maybe respectively driven based on the obtained current gain values of eachsub pixel.

Further, at S910, the individual power consumptions of each of aplurality of display modules may be calculated based on a gray scalevalue of an image displayed on each of a plurality of display modulesand the power information of each sub pixel per gray scale. The powerinformation of each sub pixel per gray scale of an image may bepreviously stored in the display apparatus or received from an externaldevice (e.g., set-top box, user terminal, server, and so on).

Meanwhile, a plurality of display modules may be implemented as an LEDcabinet including a plurality of LED devices, and each sub pixel may beimplemented as one among red, green and blue sub pixels.

According to the various exemplary embodiments of the presentdisclosure, because the color shift phenomenon according to the increaseof the current inputted to each sub pixel may be prevented, the screenquality provided to a user may be enhanced. Thus, contrast of a low grayscale image may be maximized without a color shift, and the consumedelectrical power of a high gray scale image may be reduced.

Meanwhile, the methods according to the various exemplary embodiments ofthe present disclosure may be implemented by a software/hardware upgradeof a display apparatus.

Further, there may be provided non-transitory computer readablerecording medium storing a program for consecutively performing thedriving method according to an exemplary embodiment.

The non-transitory computer readable recording medium indicate mediumwhich store data semi-permanently and can be read by machine, ratherthan medium for storing data temporarily, such as register, cache, ormemory. Specifically, the various applications or programs describedabove may be stored and provided in non-transitory computer readablerecording medium such as a CD, DVD, hard disk, Blu-ray disk, USB, memorycard, or ROM.

The foregoing exemplary embodiments and advantages are merely exemplaryand are not to be construed as limiting. The present teaching can bereadily applied to other types of apparatuses. Also, the description ofthe exemplary embodiments is intended to be illustrative, and not tolimit the scope of the claims.

What is claimed is:
 1. A display apparatus, comprising: a displaycomprising a plurality of display modules; a display driver comprising aplurality of driving modules respectively connected to the plurality ofdisplay modules; a storage configured to store current informationconcerning the plurality of display modules; and a processor configuredto calculate a peak luminance level of each of the plurality of displaymodules based on individual power consumptions of each of the pluralityof display modules, and control the plurality of driving modules usingthe current information stored in the storage based on the calculatedpeak luminance level.
 2. The display apparatus of claim 1, wherein eachof the plurality of display modules comprises sub pixels, and thecurrent information comprises current control information according toluminance of each sub pixel of the plurality of display modules.
 3. Thedisplay apparatus of claim 2, wherein the current control information iscalibrated based on a luminance characteristic and a color shiftcharacteristic according to a plurality of current levels of each subpixel of the plurality of display modules.
 4. The display apparatus ofclaim 3, wherein the processor is further configured to obtain, from thestorage, a current gain value of each sub pixel of the plurality ofdisplay modules, and control a driving state of each of the plurality ofdriving modules based on the obtained current gain values to reach therespective calculated peak luminance levels.
 5. The display apparatus ofclaim 1, wherein the processor is further configured to calculate a peakluminance level of each of the plurality of display modules based on: amaximum power consumption among the individual power consumptions ofeach of the plurality of display modules; and a rated capacity of eachof the plurality of driving modules.
 6. The display apparatus of claim5, wherein the storage further stores luminance level information of aplurality of power levels provided to each of the plurality of displaymodules, and the processor is further configured to determine areference display module of the plurality of display modules, thereference display module consuming more power than remaining displaymodules of the plurality of display modules, determine a power increaseof the reference display module, determine a corresponding powerincrease of each remaining display module based on a power increase ofthe reference display module, and calculate a peak luminance level ofeach display module based on a maximum power amount calculated for eachdisplay module and the luminance level information of each of theplurality of power levels.
 7. The display apparatus of claim 5, whereinthe storage further stores the luminance level information of aplurality of power levels provided to each of the plurality of thedisplay modules, and the processor is further configured to determine areference display module of the plurality of display modules, thereference display module consuming more power than remaining displaymodules of the plurality of display modules, calculate a reference peakluminance level of the reference display module based on maximumluminance level information of each of the plurality of power levels,and calculate a peak luminance level of each of the remaining displaymodules based on the calculated reference peak luminance level.
 8. Thedisplay apparatus of claim 1, wherein the storage further stores powerinformation of each sub pixel per gray scale of an image, and theprocessor is further configured to calculate a power consumption of eachof the plurality of display modules based on a gray scale value of animage displayed on each of the plurality of display modules and thepower information of each sub pixel per gray scale.
 9. The displayapparatus of claim 1, wherein each of the plurality of display modulescomprises an LED cabinet comprising a plurality of LED devices, and thecurrent information comprises current information corresponding to eachof a red LED, a green LED and a blue LED.
 10. A method of driving adisplay apparatus including a plurality of display modules respectivelyconnected to a plurality of driving modules, the method comprising:calculating a peak luminance level of each of the plurality of displaymodules based on individual power consumptions of each of the pluralityof display modules; and driving the plurality of display modules usingcurrent information corresponding to each of the plurality of displaymodules based on the calculated peak luminance level.
 11. The method ofclaim 10, wherein each of the plurality of display modules includes subpixels, and the current information comprises current controlinformation according to luminance of each sub pixel of the plurality ofdisplay modules.
 12. The method of claim 11, wherein the current controlinformation is calibrated based on a luminance characteristic and acolor shift characteristic according to a plurality of current levels ofeach sub pixel of the plurality of display modules.
 13. The method ofclaim 12, wherein the driving the plurality of display modulescomprises: obtaining a current gain value of each sub pixel of theplurality of display modules; and driving the plurality of displaymodules based on the obtained current gain value, to reach therespective calculated peak luminance levels
 14. The method of claim 10,wherein the calculating the peak luminance level comprises calculating apeak luminance level of each of the plurality of display modules basedon: a maximum power consumption among the individual power consumptionsof each of the plurality of display modules; and a rated capacity ofeach of the plurality of driving modules.
 15. The method of claim 14,wherein the calculating the peak luminance level comprises: determininga reference display module of the plurality of display modules, thereference display module consuming more power than remaining displaymodules of the plurality of display modules; determining a correspondingpower increase of each remaining display module based on a powerincrease of the reference display module; and calculating a peakluminance level of each display module based on luminance levelinformation of each of the plurality of power levels and a maximum poweramount calculated for each display module.
 16. The method of claim 14,wherein the calculating the peak luminance level comprises: determininga reference display module of the plurality of display modules, thereference display module consuming more power than remaining displaymodules of the plurality of display modules; calculating a referencepeak luminance level of the reference display module based on maximumluminance level information of each of the plurality of power levels;and calculating a peak luminance level of each of the remaining displaymodules based on the calculated reference peak luminance level.
 17. Themethod of claim 10, wherein the calculating the peak luminance levelcomprises calculating the power consumption of each of the plurality ofdisplay modules based on power information of each sub pixel per grayscale of an image and a gray scale value of an image displayed on eachof the plurality of display modules.
 18. A display apparatus comprising:a plurality of display modules; a plurality of driving modulesconfigured to respectively drive the plurality of display modules; and aprocessor configured to control the plurality of driving modules todisplay an image on the plurality of display modules, determine a highpower driving module among the plurality of driving modules based onpower required by each of the plurality of driving modules to displaythe image, determine a power increase based on power consumed by thehigh power driving module and a power capacity of the high power drivingmodule, and drive another driving module of the plurality of drivingmodules based on the power increase.
 19. The display apparatus of claim18, wherein the processor is further configured to determine the powerincrease by dividing the power capacity by power required by the highpower driving module to display the image, and apply power to theanother driving module at an increased level corresponding to an initialpower consumption of the another driving module multiplied by the powerincrease rate.
 20. The display apparatus of claim 18, wherein theprocessor is further configured to determine the power increase based ona difference between power required by the high power driving module todisplay the image and the power capacity, and apply power to the anotherdriving module at an increased level corresponding to a sum of aninitial power consumption of the another driving module and the powerincreased multiplied by a weighted value corresponding to the anotherdriving module.